ACAPULCO, Guerrero - A strong earthquake has been felt in Mexico City.

The country's seismic institute did not immediately issue a magnitude after the Sunday morning temblor, and there were no immediate reports of injury or damage, but the seismic alarm had gone off and authorities warned people to stay away from elevators and windows.

The temblor follows a moderate 5.21 earthquake that rocked parts of southern Mexico earlier Sunday. There were also no reports of injuries or damage from that quake.

Mexico's National Seismology Institute said the first temblor struck at 9:27 a.m. (10:27 ET) and was centered about 5 kilometers (less than 3 miles) south of Coyuca de Benitez in the southern state of Guerrero. Mexico City Mayor Miguel Angel Mancera also reported the first quake on his official Twitter account.